This invention relates to an improved electrolytic capacitor.
In particular the invention in the instant application relates to an electrolytic capacitor having aluminum anode and cathode members and exhibiting a long life in a wide temperature range and at a medium to high operating voltage.
An aluminum electrolytic capacitor capable of exhibiting a relative long life in an extended temperature range is disclosed in Burger et al. Canadian Pat. No. 694,909.
This patent shows an electrolytic capacitor having an aluminum anode and an aluminum cathode separated by an insulating spacer impregnated with an electrolyte. As the electrolyte a solution in dimethylformamide and ethylene glycol of boric acid and citric acid and an organic amine.
The scintillation (or breakdown) voltage of this electrolyte is high. For example at 85.degree. C. on aluminum it is about 410V. Capacitors employing this electrolyte have good electrical properties when operated at voltages up to about 200V. However when operated at voltages in excess of 200V these capacitors frequently generate a large amount of gas and show failures due to the development of shorts.